Blue light treatment of Pseudomonas aeruginosa: strong bactericidal activity, synergism with antibiotics and inactivation of virulence factors

Grzegorz Fila , Anna Kawiak , Mariusz Grinholc


Pseudomonas aeruginosa is among the most common pathogens responsible for both acute and chronic infections of high incidence and severity. Additionally, P. aeruginosa resistance to conventional antimicrobials has increased rapidly over the past decade. Therefore, it is crucial to explore new therapeutic options, particularly options that specifically target the pathogenic mechanisms of this microbe. The ability of a pathogenic bacterium to cause disease is dependent upon the production of agents termed ‘virulence factors’, and approaches to mitigate these agents have gained increasing attention as new antibacterial strategies. Although blue light irradiation is a promising alternative approach, only limited and preliminary studies have described its effect on virulence factors. The current study aimed to investigate the effects of lethal and sub-lethal doses of blue light treatment (BLT) on P. aeruginosa virulence factors. We analyzed the inhibitory effects of blue light irradiation on the production/activity of several virulence factors. Lethal BLT inhibited the activity of pyocyanin, staphylolysin, pseudolysin and other proteases, but sub-lethal BLT did not affect the production/expression of proteases, phospholipases, and flagella- or type IV pili-associated motility. Moreover, a eukaryotic cytotoxicity test confirmed the decreased toxicity of blue light-treated extracellular P. aeruginosa fractions. Finally, the increased antimicrobial susceptibility of P. aeruginosa treated with sequential doses of sub-lethal BLT was demonstrated with a checkerboard test. Thus, this work provides evidence-based proof of the susceptibility of drug-resistant P. aeruginosa to BLT-mediated killing, accompanied by virulence factor reduction, and describes the synergy between antibiotics and sub-lethal BLT.
Author Grzegorz Fila (IFB)
Grzegorz Fila,,
- Intercollegiate Faculty of Biotechnology UG
, Anna Kawiak (IFB/IB/DBiotech)
Anna Kawiak,,
- Department of Biotechnology
, Mariusz Grinholc (IFB/IB/DBiotech)
Mariusz Grinholc,,
- Department of Biotechnology
Journal seriesVirulence, ISSN 2150-5594, (A 35 pkt)
Issue year2017
Publication size in sheets1.00
Keywords in EnglishPseudomonas aeruginosa, blue light treatment, elastases, hemolysins, lipases, motility, photoinactivation, proteases, virulence factors
ASJC Classification2725 Infectious Diseases; 2726 Microbiology (medical); 2403 Immunology; 2404 Microbiology; 2405 Parasitology
Languageen angielski
LicenseOther; published final; Uznanie Autorstwa - Użycie Niekomercyjne (CC-BY-NC); with publication
Not used for evaluationyes
Score (nominal)0
Publication indicators Scopus SNIP (Source Normalised Impact per Paper): 2016 = 1.339; WoS Impact Factor: 2017 = 3.947 (2) - 2017=5.700 (5)
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UwagiArtykuł został zgłoszony do parametryzacji za lata 2013-2016
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